Being a science journalist has to be one of the most difficult jobs I can think of, requiring both common journalism skills as well as an ability to understand and judge the importance of claims in a wide variety of obscure specializations. Still -- a lot of it is very bad. Which is a shame, since so many people get most of their knowledge about contemporary science through the news.

Fortunately, there are certain strategies that can help you understand what is really going on when you read a piece of science journalism. As an example, let's consider the breaking news about the cave linked to John the Baptist that has just been found in Israel.

TZOVA, Israel (Reuters) - A British archeologist has dug up evidence linking John the Baptist to a cave used for bathing rituals in hills near Jerusalem in what he said could be one of the biggest recent finds for Christian history.

Shimon Gibson, who has been digging in the Holy Land for nearly three decades, told Reuters he believed the cave, hewn 24 yards deep into a rocky hillside, might also have been visited by Jesus as well as New Testament preacher John.

Okay. For a start, these claims seem pretty grandiose. I don't know anything about archeology, and precious little about Biblical history, so for all I know this guy could be completely accurate. But you do worry a little when scientists not only make absolutely fantastic claims, but seem willing to extrapolate far beyond what they have actually found evidence for (in this case, talking about Jesus). There is pressure to make your findings sound interesting to the public, and sometimes we get overly enthusiastic, but this is definitely a warning sign.

Discovered by Gibson in 1999, excavations at the cave since then have revealed a large bathing pool as well as objects used for anointing rituals that would be quite different from those used by most Jews there nearly 2,000 years ago.

Gibson, 45, said evidence of specific links to John at the site came from drawings made 400 to 500 years later, which portrayed him in a similar way to other Byzantine art. One of the pictures also showed John's severed head.

Perhaps this is just me, but that last paragraph makes no sense. Are the drawings at the site, or are there drawings elsewhere that link John to the site? Why do we care that he is portrayed in a similar way to other Byzantine art? How do we know that the drawings are of John the Baptist? Most of all, do the conclusions being reported here rely on the assumption that there are no distortions that might creep into an oral record over a period of 400 years?

"Nothing like this has been found elsewhere," Gibson said. "It is the first time we have finds from the early baptismal period ... It is an amazing discovery that happens to an archeologist once in a lifetime."

The discovery, 15 minutes drive into hills west of Jerusalem, is due to be announced officially Tuesday, ahead of the launch of a book by Gibson.

Ding ding ding! He's writing a book. Already has written one, in fact. So there might be some conflict of interest between appropriate scientific skepticism and the selling of the story. Also, why is the finding only being announced now? It must have taken some time to write the book -- presumably the archeological finding would have been published in a reputable journal some time back?

Any discovery of sites linked to the Bible is certain to stir controversy and its share of skepticism, but Gibson said he had carried out many tests to satisfy himself that his theory was sound. The Bible describes John performing baptisms -- including that of Jesus -- in the River Jordan, a good 25 miles east over the Judean desert.

But Gibson said the site at Tzova could be linked to early years "when John sought solitude 'in the wilderness."'

Okay, now we are told that there is actually a conflict between what we know about John and where the cave was found. And a flimsy explanation is offered. But we are supposed to be reassured, since Gibson himself has carried out many (unspecified) tests. Notice that there are no outside experts quoted in the article. Even when there are, you need to take what they say with a grain of salt, since they have typically not had a chance to review the claimed findings in any detail, and have to rely on their general expertise in the subject area. When they are completely absent, it's a bad sign.

"In addition to John the Baptist, there's a possibility that Jesus used this cave as well," said Gibson.

Yes. There is also the possibility that Alexander the Great slept there, and the Loch Ness monster has visited. There are lots of possibilities. If there were any actual evidence that Jesus had been there, do you think we'd spend so much time talking about John the Baptist?

Gibson said he was sure the cave could not have been put to other uses -- as a water store or a hideout for example -- or that it was used by any other group carrying out similar types of rituals around the same time as John.

"I don't believe in that kind of coincidence," said Gibson, who said he was not religious himself. "Pilgrims will be flocking to the cave."

What coincidence? That some non-famous person was using the cave for some good reason? Most of the people alive two thousand years ago were not celebrated figures from the Bible, and most archeological findings are not going to represent important events in the lives of famous people.

Again, I have no expertise in this actual area, and for all I know Gibson may turn out to be completely correct and his findings may go down in history as a major breakthrough. But we don't have evidence for that from this story. The journalist can always say that they are simply reporting what they have been told. But I don't really think that is the end of the journalist's job -- it's perfectly appropriate to exercise some judgement about the claims being made. Unfortunately, if you spend just a day talking to outside experts and verifying the credibility of the story, your rivals will get the story out before you, and that's the major criterion for success in the news business. So it's up to the readers to use their own judgement.

My personal experiences have been with stories about science. But something tells me that stories about politics are not that different.